Personal computers such as the IBM family of personal computers and the so-called IBM clones or compatibles are produced with an "open architecture" design for allowing additional functions to be later added to the computer. As a result, a number of manufacturers produce various printed circuit boards or (sometimes called "I/O cards" or "expansion cards") which are mounted in the computer for later expanding its available functions. For instance, expansion cards can be installed in the computer to provide a hard disk drive controller, a color/graphics monitor, networking, memory expansion, printer ports, accelerator functions, modems, and the like.
In order to facilitate connection of expansion cards to the computer circuitry, the computer has a number of expansion slots on the rear panel of the computer chassis. The expansion slots have separate removable cover plates for radiation shielding and for serving as dust covers for the expansion slots. The expansion card has a long, narrow edge connector which projects from the bottom edge of the card and is plugged into an electrical port commonly referred to as an expansion card socket. The edge connection has a number of parallel metal plated male contacts which make contact with corresponding spring-loaded female contacts in the expansion card socket. The expansion socket may be ISA (Industry Standard Architecture) or the newer PCI (Preferred Component Interconnect) type socket. PCI sockets are usually physically longer than the older ISA sockets. Therefore, PCI circuit cards tend to be longer than ISA circuit cards. The cover plate originally used for the expansion slot is usually thrown away when the expansion card is added. The old cover plate is replaced by a fill-length mounting bracket fastened to the rear edge of the expansion card. This mounting bracket together with the card's connection to the socket at the base of the computer chassis provide a dual means of support at the bottom and rear edge of the card for stabilizing the expansion card (holding it in a fixed upright position) inside the unit. The mounting bracket also aids in resisting the tendency of the female contacts of the card socket pushing the male contacts of the expansion card out of the card socket.
The mounting bracket is a specially fabricated metal piece having a flat face to cover the expansion slot (to serve as the radiation shield and dust cover in place of the removed cover plate). The bracket also has a tab at its top for fastening to the top inside edge of the computer chassis by the screw that held the expansion slot's original cover plate in place. The manufacturer of the expansion card typically fastens the special mounting bracket to the expansion card during assembly of the expansion card. The bracket is rigidly fastened to the edge of the card by riveting or by fasteners such as screws.
The above-noted expansion card mounting system typically works fine in an office or home environment. In an office or home environment, the computer is generally isolated from vibration or shock. In industrial, transportation, and military applications, the computer can often be subject to shock or vibration which will cause the expansion card to dislodge or to vibrate and cause the male and female contacts to intermittently or permanently lose engagement. It would be highly desirable to provide a stabilizer which would prevent inadvertent dislodgement between the male and female contacts due to adverse environmental conditions.